05
3.5 Over voltage protection
The over voltage sense circuitry and reference shall reside in packages that are separate
and distinct from the regulator control circuity and reference. No single point fault shall be
able to cause a sustained from the regulator control circuity and reference. No single point
fault shall be able to cause a sustained as defined in Table.
3.6 Short circuit
An output short circuit is defined as any output impedance of less than 0.1 ohms. The power
supply shall shut down and latch off for shorting the +3.3 VDC,+5 VDC,or+12 VDC rails to
return or any other rail. Shorts between main output rails and +5VSB shall not cause any
damage to the power supply. The power supply shall either shut down and latch off or fold
back for shorting the negative rails.+5VSB must be capable of being shorted indefinitely,
but when the short is removed, the power supply shall recover automatically or by cycling
PS_ON#. The power supply shall be capable of withstanding a continuous short-circuit to
the output without damage or overstress to the unit
3.7 No load operation
No damage or hazardous condition should occur with all the DC output connectors
disconnected from the load. The power supply may latch into the shutdown state.
Figure 2. is a reference for signal timing for main power connector signals and rails.
Figure 2. PS-OK Timing Sequence
output
+12 VDC
+5 VDC
+3.3 VDC
Minimum
13
5.5
3.6
Nominal
15
6
4
Maximum
17
7
5
Unit
Volts
Volts
Volts
4.1 Signal timing drawing
4. TIMING
